1. Field of the Invention
The present invention relates to a left ventricle mapping probe for mapping cardiac potentials at different points on the inner wall of a left ventricle of a heart.
2. Description of the Prior Art
Heretofore difficulties have been encountered in mapping the left ventricle of the heart, such as difficulties in crossing or passing through the aortic valve, accidental perforation of a blood vessel and the problem of maintaining good wall contact with the mapping electrodes.
Also, the stiffness required in a straight mapping lead necessary to maintain wall contact with the interior wall surface of the left ventricle can result in perforations and other complications in very sick hearts. Also, the twisting of a straight lead to obtain the desired wall contact may result in trauma to the aortic valve and left ventricular apex.
Heretofore it has been proposed in the non-analogous Stevens U.S. Pat. Nos. 3,485,234 and 3,585,707, the nonanalogous Olsten, Jr. et al U.S. Pat. No. 4,425,915 and the non-analogous Gould et al U.S. Pat. No. 4,586,923 to provide a torque transmitting catheter.
Further, it has been proposed in the Muench U.S. Pat. No. 3,769,984, the Sabel U.S. Pat. No. 3,949,757, the Goldreyer U.S. Pat. No. 4,365,639 and the Beranek U.S. Pat. No. 4,608,986 to provide straight wire conductors in an endocardial lead.
Also, different techniques heretofore have been proposed for mounting sleeve electrodes on the exterior of an endocardial lead and around an uninsulated wire conductor end portion wound around the outer surface of the lead body in the Gold U.S. Pat. No. 4,444,195 and the Beranek U.S. Pat. No. 4,592,372.
Also, various types of mapping probes have been previously proposed. In this respect, in the Halvorsen U.S. Pat. No. 4,289,138 there is proposed an electrode assembly for making potential measurements in a heart including contact ferrules mounted adjacent the end of an insulated wire conductor.
In the Kline U.S. Pat. No. 4,172,451 there is disclosed a multicontact plunge electrode. A distal end portion of the electrode is stiffened and bent at a substantial angle, e.g. 90.degree., to a proximal portion of the electrode so as to provide a generally L-shaped endocardial electrode assembly which can be used to measure electrical potentials at multiple depths within the myocardial wall of a heart.
In the Gelinas et al U.S. Pat. No. 4,522,212 there is disclosed an endocardial electrode assembly of three or more spring legs adapted to be inserted into the heart and having sets of electrodes on respective spring legs. The sets of electrodes comprise or define a distinctive geometric pattern over the ventricle-contacting span of the legs.
Further, in the Chilson et al. U.S. Pat. No. 4,694,147 there are shown mapping electrode spring leg assemblies coupled to a push-pull control rod which enables the ellipsoid envelope formed by the electrode assemblies to be adjusted.
As will be described in greater detail hereinafter, the mapping lead of the present invention has a main body portion which is torque controlled and which has a flexible end portion that has a plurality of electrodes mounted thereon, that has a preformed set and that can be accurately rotated within a chamber of the heart, such as a left ventricle, when the proximal end of the main body portion is rotated, thereby to enable a physician to map, in steps, electric potentials at different positions on the inner wall surface of a heart chamber, such as the left ventricle.